Power-transmission mechanism



Oct. 7, 1941. H. SINCLAIR POWER-TRANSMISSION MECHANISM Original Filed Feb. 10, 1939 2 sheets -sheet l zo a2 29 h i 47R 42R 97/? 26 43R Oct. 7, 1941. H. SINCLAIR POWER-TRANSMISSION MECHANISM Original Filed Feb. 10, 1939 2 Sheets-Sheet '2 4 Patented 'Oct. 7, 194i;

UNITED STATES PATENT OFFICE.

POWER-TRANSMISSION MECHANISM Harold Sinclair, Kensing'ton, London, England Original application February 10, 1939, Serial No.-

255,617. Divided and this application Angus 1c, 1940, Serial No. 352

as to enable it to transmit torques in both'senses.

A further object is to provide synchronizing gcouplings having improved control means.

A gear wheel 28 journalled on the eountershaft is connected through an idler wheel 29 with a gear wheel 30 fixed to the output shaft 3|. The input shaft it, which normallyrotates clockwise as viewed from the left of Fig. 1, is provided with a left-handed helical thread 32 of steep pitch on which is engaged a nut 33 having teeth '34. These Other objects and advantages of the invention will .be apparent from the example of an embodiment thereof applied to reversing gearing, which is shown in the accompanying diagrammatic drawings, in which:

Fig. 1 is a sectional side elevation of part' of -a marine power plant,

'Fig. 2 is a sectional side elevation, to a larger scale, of a part of Fig. 1, and- Fig. 3 is aperspective'view of control mechanism for the power plant of Fig. 1.

The plant shown in Fig. 1 includes a reversing gear of the countershaft type. The input shaft in of the reversing gear is connected to an internal-combustion engine II by a hydraulic coupling I2 of the kinetic type associated with controllable planetary gearing adapted temporarily to impart a slow reverse rotation to the shaft in by the agency of power applied by the engine. The hydraulic coupling includes an impeller I 3 fixed to the engine crankshaft l4, and a runner i5 fixed to the shaft III. A casing l6 fixed to the impeller carries one or more pairs of planet pinions, such as l i and l 8, one of which is slightly larger than the other. The larger pinion l I meshes with a sun wheel l9 rigid with the shaft III, while the smaller pinion l8 meshes with a sun wheel fast on the hub of a brake drum 2| which is journalled on the shaft 10.. A brake member 22, pivoted on a fixed pin 23, can be engaged with the drum 2| in consequence of upward movement of a push rod 24. When the drum 2| is held stationary and the engine is running, the planet pinions are rolled by the member l6 round the stationary sun wheel 20 and thereby impart a slow backward rotation to the shaft ID.

The shaft I ii is fixed to a'gear wheel meshing teeth are engageable with teeth 35 on a drum 36 fixed to the output shaft 3|. The nut 33 carries one or more pawls such as 31, which are biased outwards by springs (not shown) and which face in the trailing direction so that, when the shaft 10 is rotating forwards .faster than the shaft 3|.

these pawls can ratchet over the teeth 35.

- A locking sleeve 38, having internal axial splines 39, is engaged with axial splines 40 on the nut 33. Th splines are so arranged that, when the teeth 3 and 35 are fully engaged together, the

locking sleeve 38 can be slid to-the left to bring its splines 39' into engagement-with a. splined I flange 4| fixed on the shaft ill, whereby the nut with a gear wheel 26 fixed to a countershaft 21. 5s

33 is locked to the shaft 10. The locking sleeve 38 is coupled to the nut 33 by'a lost-motion con' nection comprising a radial pin 42 fixed to the sleeve 38 and engaging in a longitudinal groove 43 in the surface of the nut 33. The amount of lost motion permitted slightly exceeds the axial dimension of the teeth 35.

A similar coupling is adapted to connect the countershaft 21 to the gear wheel .28, the only difierence being that the countershaft coupling has a right-handed helical thread and the pawls point the other way. The parts of the countershaft coupling have the same reference numerals as corresponding parts of the first described coupling, but distinguished by the reference letter R.

The control mechanism will now be described with reference toFig. 3. The locking sleeves 38 and 38R. of the forward and reverse free-wheel couplings are provided respectively with circumferential grooves 44 and 44R, and these grooves are engaged respectively by pins on the ends of two levers 45 and 45R mounted to rock about a' transverse shaft 46, the arrangement being such that, when these rocking levers are in their mid positions, both couplings are in the freewheeling condition, as shown, in Fig. 1. An actuating lever 41 is fixed to the shaft 46 and carries a pin 43 which is parallel to the shaft 46 and to a pin 49 fixed to the rocking lever 45. A torsion spring 50is disposed around the boss of the rock-. ing lever 45 and its ends are disposed respectively on opposite sides of the pins 48 and'49, the arrangement being such that the spring 50 tends to maintain the levers 45 and 41 in the relationship shown, in which-the pins 48 and 49 are adjacent to each other. The lever 41- is provided with arecessil' accommodating the free end of the the shaft 45 by a link 55 and a crank 55. Whenthe handle 52 is in the short limb N of the gate as shown, or level'with this limb, the rocking levers 45 and 45R are normally in their mid positions so that the locking sleeves 38 and 38R are in the positions shown in Fig. 1 and both synchronizing couplings are in condition to operate as free wheels.

A bar 51 is mounted on a crank 58. fixed to a' shaft 58 journaled by means not, shown. A lever 5| fixed to the shaft 59 is pivoted-to the push rod 24 that actuates the brake of the planetary gearing and a tension spring 52 normally maintains this brake disengaged and holds the crank 58 against a fixed stop 50. I

A bar 53 is mounted on a crank 54 and disposed on the side of the handle 52 opposite to the bar 51. The bar 53 is mounted on a crank 64 fixed to a shaft 55 journalled by means not shown. A lever 51 fixed to the shaft 55 is pivoted to a push rod 59 which when raised opens the throttle valve ill of .the engine (Fig. l). A tension spring 68 normally holds the crank 54 against a fixed stop 55 and thus maintains the throttle valve in the idling position.

This mechanism operates as follows. It will be assumed that the handle 52 is in the position shown, which represents neutral. The engine l is started, the input shaft ll) rotates forward and both free-wheel couplings over-run, the pawls 31 and 31R ratcheting over the teeth 35 and 35R respectively. The handle 52 is now pulled to the point NB, so that it rocks the bar 51, causing the input shaft It to be arrested and temporarily urged backwards by'the planetary gearing, the

slip in the hydraulic coupling l2 permitting the engine to continue idling. Both free-wheel couplings thereupon engage the nuts 33 and 33R moving to the left against the flanges 4| and 4 IR and bringing the teeth 34 and 34B cleanly into mesh respectively with the teeth 35 and 35B, under the guidance of the pawls 31 and 31R. The gear is thus locked solid, the shaft i being at rest and the brake drum 2| slipping under the brake 22. In this condition the pins 42 and 42R age at the right-hand ends of the grooves 43 and The handle 52 is now moved say to position F13. The control shaft 46 is consequently rocked anticlockwise so that the locking sleeve 38 of the forward-drive synchronizing coupling is moved to the left, through the agency of the spring 50,

.until its splines 39 engage with the splined flange 4|, and thus this coupling is rendered bi-directionally locked. At the same time the-spring 50R urges the reverse-drive coupling locking sleeve 38R to the right; but, since the pin 42B is already at the right-hand end of the groove 43R, the sleeve 38R does not move immediately, the lost motion provided by the recess |R in the actuating lever 41 permittingthe necessary relative angular displacement of the shaft 48 and the lever 45R. The

handle 52 is now moved to position i, with the result that the brake 22 is disengaged by the spring 62 and the engine throttle valve "is opened by the displacement of the bar 53. The output shaft 3| is now driven forwards through the locked forward-drive synchronizing coupling, and the reverse-drive synchronizing coupling disengages,

the nut 33R running out to its extreme right-' hand position where the pawls 81R are out of register with the teeth 35R, and the locking sleeve 38R. moving to the right from-the position shown in Fig. 1 under the influence of the spring 55R. To reverse the rotation of the output shaft 3|, the handle 52 is moved through position FE and urged towards positior RB. The movement to position FB shuts the engine throttle I8 and applies the back-turning brake 22 so that the shafts Hi and 3| are arrested. The movement towards position RB rocks the control shaft 45 clockwise, so that the locking sleeve 38 is displaced through the agency of the spring 53 to the position shown in Fig. 1. Since the inertia of the vessel causes the forward drive coupling to remain engaged under over-running torque, the pin 42 abuts against the right-hand end of the slot 43 and prevents further displacement of the locking sleeve 38 to the right. Meanwhile the locking sleeve 38R has been displaced through the agency of the spring 50R to the position shown in Fig. 1, so that the reverse-drive coupling is in free-wheeling condition. Since the splines 33R are not in register with the splines of the flange 4|R, further displacement of the locking sleeve 3813. to the left is prevented.

When the input shaft l0, and with it the output shaft 3| attempt to turn in the reverse direction under the influence of the planetary gear, the reverse-drive coupling also engages, the nut 33R moving to its extreme left-hand position and the teeth 34R. meshing cleanly with the teeth 35R under the guidance of the pawls 31R. The spring 50R thereupon moves the locking sleeve 38R into engagement with the splined collar 4|R, so that the reverse-drive coupling is bi-directionally locked. The pin 49R co-operates with the recess I 5|R to prevent the handle 52 from reaching the point RB on the gate before the reverse-drive coupling has become bi-directionally locked. The handle52 is now moved round the corner RB of the gate to the point R, so that the brake 22 is -released and the engine throttle is opened. The input shaft l8 now rotates forwards, driving the output shaft backwards through the reverse-drive coupling, and the nut 33 of the forward-drive coupling runs out to its extreme right-hand position where the pawls 31 are out of register with the teeth 35, the locking sleeve 38 moving to the influence of the spring 50.

The change from reverse to forward gear is effected similarly.

While the example of the improved synchronizing coupling herein described is embodied in reversing gearing, it is to be understood that the improved coupling, as defined in the following claims, is also applicable to other kinds of power transmission mechanism.

I claim: I

l. A synchronizing coupling comprising a first member having a set of jaw-clutch teeth, a second member rotatable relatively to said first member, an intermediate member having a set of jawclutch teeth and drivably connected to said second member by cooperation helically disposed torquetransmitting surfaces, said intermediate member being longitudinally movable relatively to said first andsecond members so as to interengage and disengage said sets 01' clutch teeth, a subsidiary ratchet drive capable of coupling said first and intermediate members andv eflecting engagement of said sets of clutch teeth without clashing on relative displacement or said cooperating helical surfaces in one sense, and control means operable for relatively displacing said first member and said intermediate member, at least in part axially, from a disengaged position, in which said subsidiary ratchet drive is inoperative and the coupling is iii-directionally 'free, to an engaged position, in which said subsidiary ratchet drive is operative and the coupling is in free-wheeling condition.

2, A synchronizing coupling comprising a first member having a set of jaw-clutch teeth, a second member rotatable relatively to said first member,

an intermediate member having a set of jawclutch teeth and drivably connected to said second member by cooperating helically disposed torquetransmitting surfaces, said intermediate member being longitudinally movable relatively to said first and second members so as to interengage and disengage said sets of clutch teeth, a pawl on one of said toothed members engageable with teeth on the other; of said toothed members and so positioned as to efiect interengagement of said sets of clutch teeth without'clashing on relative displacement oisaid cooperating helical surfaces in one sense, and control means operable for relatively displacing said first member and said intersesamon one oi said toothed members engageable with teeth on the other of said toothed members and '80 positioned as to permit engagement of said toothed members without clashing on relative angular displacement or said first and second members in .one sense, a locking member constrained to rotate with and slidable relatively to said intermediate member, and coupled thereto by a connection limiting the relative axial displacement oi" said locking and intermediate members, means .constrained to rotate with said second member and capable or being clutched to thereon in consequence of relative rotation between said intermediate and second members, said intermediate member having teeth engageable with the teeth of said first member, a pawl, on one of said toothed members engageable with teeth on the other of said toothed members and so positioned as to effect engagement of said toothed members withoutclashing on relative angular displacement 01' said first and second members in one sense, a locking member conmediate member, at least in part axially, from a disengaged position, in which said pawl is out of the ,path of the teeth with which it cooperates and the coupling is bi-directionally free, to an engaged position, in which said pawl is in the path of the teeth with which it cooperates and the coupling is in free-wheeling condition.

3. A synchronizing coupling comprising a first member having a set of jaw-clutch teeth, a second strained to rotate with said intermediate member and coupled thereto by a connection limiting the relative axial displacementbtsaid locking and intermediate members in one sense, said locking member having splines ,so positioned as to be engageable with splines on said second member member rotatable relatively to said first member,

an intermediate member having a set of jawclutch teeth and drivably connected to said second member by cooperating helically disposed torque-transmitting surfaces, said intermediate member being. longitudinally movable relatively to said first and second members so as to inter- .engage and'disengage said sets of clutch teeth,

a pawl on one of said toothed members engageable with teeth on the other of said toothed members and so positioned as to eflect interengager ment of said sets of clutch teeth without clashing on relative displacement of said cooperating heli- 'cal surfaces in one sense, and control means operable for displacing said intermediate member relatively to said first and second members from a disengaged position, in which said pawl is out of the path of the teeth with which it cooperates to a free-wheeling position in which said pawl is in the path of said last-mentioned teeth, said control means permitting automatic displacement of. said intermediate member from said freewheeling position to a driving. position 'in which it is in mesh with the teeth of said first member. -4. A synchronizing coupling comprising a toothed first'member, a second member co-axial with and rotatable relatively to said first'member, an intermediate member so mounted on said only when the teeth of said first and intermediate members are meshed together, and control means operable for displacing said locking member axially relatively to said first and second members.

6, A- synchronizing coupling comprising a toothed first member, a second member co-axial with and rotatable relatively to said first member, an intermediate member so mounted on said second member as to be caused to move helically thereon in consequence of relative rotation between saidintermediate' and second members, said intermediate member having teeth engageable with the teeth of said first member, a pawl on one of said toothed members engageable with I teeth'on the other 01' said toothed members and second member as to be caused to move helically thereon in'consequence or relative rotation between said intermediate and second members, said intermediate member having teeth engageable with the teeth oi said first member, a pawl so positioned as. to effect engagement r said toothed members without clashing on relative angular displacement of said first and second members in one sense, a locking member constrained to rotate with saidintermediate member and coupled thereto by a lost-motion connec- 3 tion permitting limited relative axial displacement, said locking member having splines engageable with splines on said second member only when the teeth of said first and intermediate members are meshed together, and an actuating member coupled to said lbcking member by a resilient connection arranged in parallel. witha positive lost-motion connection.

7. A synchronizing coupling comprising a first member having teeth, a second member rotatable relatively to said first member, an intermediate member co-axial with and axially movable along said second member,'said second and intermediate members having co-operating helically disposed torque-transmitting surfaces, and said intermediate member having teeth engageable with said teeth of the first member, a pawl on one oi! said first and intermediate members engageable with teeth on the other of said last-mentioned two members and so positioned as to efiect engagement of said teeth together without clashing in response to torque acting in one sense between said helically disposed surfaces, external splines on said intermediate member, a locking sleeve having internal splines co-operating with said external splines, external splines on said second -member drivably connected to said second memmember positioned to mesh with said intemal member to be moved axially by said locking sleeve, when the coupling is bi-directionally tree, in sucha direction as to bring said pawl into the path of the teeth with which it co-operates while permitting said intermediate member to move in the same direction in advance of said locking sleeve.

8. A synchronizing coupling comprising a first member, a second member rotatable relatively to said first member, and unidirectional coupling means capable of coupling said first and second members together including an intermediate her and having jaw-clutch teeth engageable with jaw-clutch teeth on said first member, locking means operable only in consequence oi. engagement of said unidirectional coupling means under torque in one direction for converting said uni-. 

